1. Field of the Invention
This invention relates to a process for producing a chemical analytical slide having a bar code printed on the surface of the slide frame.
2. Description of the Prior Art
Recently, in the field of clinical tests, dry analysis using a chemical analytical slide has widely been utilized because of the superiorities in the simplicity of analytical operation and rapidity of measurement. In general, the chemical analytical slide is composed of a chemical analytical film containing the reagent reacting with a particular component of a liquid sample such as blood and a slide frame to hold the margin of the chemical analytical slide. On the slide frame, a bar code is printed due to the discrimination of products.
As such a conventional chemical analytical slide, it is known that the chemical analytical film was fixed by a combination of a flat slide frame and the other slide frame having a concavity molded by injection molding (Japanese Patent KOKAI 57-63452). Besides, it is also known that the chemical analytical slide having a hinge similar to a transparent positive film slide, the chemical analytical slide using a paper slide frame (Japanese Utility Model KOKAI 61-116350), and the chemical analytical slide of a cartridge type (Japanese Utility Model KOKAI 54-162294). However, in the case of these chemical analytical slides produced by injection molding, since the bar code was printed on each assembled slide one by one, printing speed was low thereby raising manufacturing cost.
Another chemical analytical slide was developed in order to increase the production speed. The frame of this chemical analytical slide was formed by punching a strip sheet. The chemical analytical slide is, as shown in FIG. 5 and FIG. 6, composed of an upper slide frame 1 and a lower slide frame 2 located at the upper position and the lower position respectively, and a spacer 3 and a chemical analytical slide 4 interposed therebetween. Circular openings 5, 6 are formed near the center of the upper slide frame 1 and the lower slide frame 2, and a bar code 7 is printed on a side portion of the upper slide frame 1. A film hole 8 for placing the chemical analytical film 4 is bored in the center of the spacer 3.
As the method of producing this chemical analytical slide, bar codes were printed on a strip sheet at regular intervals, and the strip sheet was successively punched to produce the upper slide frames 1. The lower frames 2 and the spacers 3 were also produced by punching other strip sheets. The chemical analytical film 4 was inserted into the film hole 8 of the spacer 3, and thereafter, the upper slide frame 1 and the lower slide frame 2 were attached by ultrasonic welding or another method to complete the chemical analytical slide (Japanese Patent KOKAI 61-51570).
However, in the case of the above chemical analytical slide, since the strip sheet was printed with each bar code in a size for each slide frame at regular intervals, it was necessary to be punchased so that the bar code came to a prescribed position. Therefore, the strip sheet should be positioned exactly both in the longitudinal direction and in the lateral direction. Furthermore, the thickness of ink in the latter part of printing was different from the thickness in the beginning causing variations in the ink concentration or the width of the lines of each bar code, or in a particular case, causing a shortage of ink. These brought errors in reading.